Assis - CPPA - Centro de Pesquisa e Psicologia Aplicada

URI Permanente para esta coleçãohttps://hdl.handle.net/11449/253737

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Viability of Toxoplasma gondii in cattle semen cryopreserved with different concentrations of cryoprotectant
(2023-01-01) Felippelli, Gustavo ; Toscano, João Henrique B. ; Texeira, Weslen F.P. ; Santos, Isabella B. ; Cruz, Breno C. ; Maciel, Willian G. ; Soares, Vando E. ; Bresciani, Katia Denise S. ; Lopes, Welber D.Z. ; Costa, Alvimar José ; Universidade Estadual Paulista (UNESP) ; Universidade Federal de Goiás (UFG) ; Universidade Brasil
Felippelli G., Toscano J.H.B., Texeira W.F.P, Santos I.B., Cruz B.C., Bresciani K.D.S, Lopes W.D.Z. & Costa A.J. 2023. Viability of Toxoplasma gondii in cattle semen cryopreserved with different concentrations of cryoprotectant. Pesquisa Veterinária Brasileira 42:e07106, 2023. Centro de Pesquisas em Sanidade Animal, Departamento de Patologia Veterinária, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista “Júlio de Mesquita Filho”, Campus de Jaboticabal, Via de Acesso Prof. Paulo Donato Castellane s/n, Zona Rural, Jaboticabal, SP 14884-900, Brazil. E-mail: gusvetfelippelli@gmail.com Toxoplasma gondii can be eliminated in bovine semen. Cryopreserved semen is often used due to the fact that artificial insemination in dairy and beef cattle provides benefits in terms of production. However, little is known regarding the viability and infectivity of T. gondii tachyzoites in cryopreserved bovine semen. In the present study, cattle semen negative for T. gondii were contaminated with 1 x 106 tachyzoites (RH strain) and cryopreserved with and without different cryoprotectants, such as DMSO (concentrations of 2.5%, 5.0%, 7.5%, 8.0% and 10.0%) and glycerol (2.25%, 2.5%, 3.0%, 5.0%, 7.5% and 10.0%), followed by freezing in liquid nitrogen (-196°C). After 24 hours, the samples were thawed and inoculated in 10 mice per cryoprotectant concentration. The mice were evaluated for clinical signs of toxoplasmosis (rough coat, diarrhea, hypoactivity and sudden death) as well as serum titers of IgM and IgG and the presence of tachyzoites in the peritoneal lavage. The results revealed that T. gondii remained infective in all samples. Clinical signs of toxoplasmosis were observed in the mice beginning with the 6th day post-inoculation (DPI) and 100% lethality was found between the 7th and 9th DPI. Viable tachyzoites were recovered from peritoneal exudate of dead mice (except for the control group), with higher mean of tachyzoite counts in the intraperitoneal lavage for 5% DMSO (±3.32 x 106), 8% DMSO (±3.53 x 106), 3% glycerol (±4.75 x 106), 7.5% glycerol (±6.26 x 106) and the absence of cryoprotectant (±3.11 x 106). Seroconversion occurred in the treated groups, with titers of IgG from 1:16 to 1:128 and IgM from 1:16 to 1:512. T. gondii viability and infectivity were maintained in cattle semen during 24 hours of cryopreservation at -196°C with and without cryoprotectant. However, further studies are necessary to determine whether cryopreserved semen contributes to the spread of toxoplasmosis through artificial insemination.
Pesquisa de anticorpos anti-Neospora caninum em bovinos leiteiros, cães e trabalhadores rurais da região Sudoeste do Estado de Mato Grosso
(Colégio Brasileiro de Parasitologia Veterinária, 2009-12-01) Benetti, Ana Helena ; Schein, Fábio Bernardo ; Santos, Thaís Rabelo dos ; Gilson Hélio, Toniollo ; Costa, Alvimar José da ; Mineo, José Roberto ; Lobato, Janaína ; Silva, Deise Aparecida de Oliveira ; Gennari, Solange Maria
Considerando a importância da neosporose interferindo na produtividade animal, avaliou-se a frequência de anticorpos anti-Neospora caninum em amostras de soros de bovinos leiteiros da Região Sudoeste do Estado de Mato Grosso, Brasil, complementando-se com amostras sorológicas colhidas de cães e de humanos que conviviam nas mesmas propriedades rurais amostradas. Um total de 1.036 amostras de soros foram analisadas, sendo 932 de fêmeas bovinas leiteiras, 37 de cães e 67 de humanos, provenientes de 24 propriedades e examinados por meio da reação de imunofluorescência indireta (RIFI). As amostras de soros humanos reagentes foram testadas novamente por Western-blotting para confirmação dos resultados. Anticorpos anti-N. caninum foram encontrados em 499 bovinos (53,5%), em pelo menos um animal positivo por propriedade, em 25 caninos (67,6%) e em sete humanos (10,5%). Não houve diferença significativa no número de bovinos positivos por faixa etária. Os resultados obtidos indicam uma ampla disseminação de N. caninum na região estudada.
Abundância e sazonalidade de dípteros (Insecta) em granja aviária da região nordeste do Estado de São Paulo, Brasil
(Brazilian Coll Veterinary Parasitology, 2008-01-01) Lopes, Welber Daniel Z. ; Costa, Fabio H. da ; Lopes, Wilton Car-Los Z. ; Balieiro, Julio Cesar de C. ; Soares, Vando E. ; Prado, Angelo P. do ; Universidade de São Paulo (USP) ; Universidade Camilo Castelo Branco ; Universidade Estadual Paulista (Unesp) ; Universidade Estadual de Campinas (UNICAMP)
Modem production systems accommodate broody hens in high densities, leading to the accumulation of excrement under the cages. This substrate is excellent for the development of sinantropic flies. Thus, the accomplishment of surveys in these places becomes essential, in order to plan better strategies of control. The present work aimed at studying the entornofauna and the seasonality of the species of dipterous present in the Crisdan poultry house located in the Municipality of Sao Joao da Boa Vista, the State of São Paulo, Brazil. In the period of January of 2001 to December of 2002, 1,012,595 flies were captured using the "jug-trap". The species were identified: Drosophi-la repleta (Wollaston, 1858), Musca domestica (Linnaeus, 1758), Ophyra spp., Hennetria illucens (Linnaeus, 1758), Fannia canicularis (Linnaeus, 1761), Chrysomya megacephala (Fabricius, 1794), and Sepsidae. More frequently D. repleta and M. domestica had added 99.47% of the dipterous. Increased rainfall and the collection months influenced the sampling of dipterous (P < 0.05). Drosophila repleta was the most abundant species, representing 91% of all captured flies. However, this diptera did not develop at the surveyed site since immatures were not captured therein.
Strategic control of cattle co-parasitized by tick, fly and gastrointestinal nematodes: Is it better to use ecto + endoparasiticide or just endectocide formulations?
(2022-01-01) Gomes, Lucas Vinicius Costa ; Teixeira, Weslen Fabricio Pires ; Maciel, Willian Giquelin ; Felippelli, Gustavo ; Buzzulini, Carolina ; Soares, Vando Edésio ; de Melo, Daniel Pacheco ; Cruz, Breno Cayero ; Rodrigues, Daniel de Castro ; Ferreira, Lorena Lopes ; Monteiro, Caio Marcio de Oliveira ; Lopes, Welber Daniel Zanetti ; da Costa, Alvimar José ; Universidade Estadual Paulista (UNESP) ; Universidade Brasil ; Universidade Federal de Goiás (UFG) ; Universidade Federal de Minas Gerais (UFMG)
Ticks, flies, and gastrointestinal helminths (GINs) significantly affect cattle productivity; thus, ectoparasiticide, endoparasiticide, and endectocide drugs have commonly been used for their control. The study aimed to compare the technical (parasites counts), productive, and financial effects of a treatment protocol comprising ecto- + endoparasiticides formulations (T01: fluazuron 2.5 mg/kg + fipronil 1.25 mg/kg and fenbendazole 5 mg/kg; n = 15) to a treatment with one formulation of endectocide (T02: ivermectin 450 μg/kg + abamectin 250 μg/kg; n = 15) over 308 days under field conditions in crossbred cattle co-parasitized by Rhipicephalus microplus, Haematobia irritans, and GINs. Bovine weight gain and return on investment (ROI) were also evaluated. Bovines from T01 received four treatments against the cattle tick and two against two GINs. For T02, four treatments were performed. Animals from T01 gained 15.4 kg more than T02 and provided a comparative ROI of 15.8. In cattle co-parasitized with R. microplus, H. irritans, and GINs, the treatment protocol used in this study with ecto- + endoparasiticidal action formulations showed better technical results regarding parasite counts and productive and financial data than the strategic treatment protocol using only an endectocide formulation.
Ivermectina e abamectina em diferentes doses e vias de aplicação contra larvas de Cochliomyia hominivorax em bolsas escrotais de bovinos recém-castrados, provenientes da região sudeste do Brasil
(2013-12-01) Lopes, Welber Daniel Zanetti ; Teixeira, Weslen Fabricio Pires ; Felippelli, Gustavo ; Cruz, Breno Cayeiro ; Maciel, Willian Giquelin ; de Matos, Lucas Vinicius Shigaki ; Pereira, João Carlos Melo ; Buzzulini, Carolina ; Soares, Vando Edésio ; dos Santos, Thais Rabelo ; de Oliveira, Gilson Pereira ; da Costa, Alvimar José ; Universidade Estadual Paulista (UNESP)
The preventive efficacy of ivermectin and abamectin administered in different routes (subcutaneous, intramuscular and pour-on) and doses (200 and 500mcg kg-1) against Cochliomyia hominivorax in the scrotal sac of cattle after castration, was evaluated. Animals from six different farms, in the state of São Paulo and Minas Gerais, Brazil were used. For each study, 30-45 uncastrated bulls, depending on the number of groups, were selected. On day zero of the study, the procedure was carried out by the method of bloody castration and the animals were treated after this process. The efficacy of ivermectin and abamectin administered via the pour-on (500mcg kg-1), subcutaneous (200mcg kg-1) as well as the efficacy of abamectin intramuscularly (200mcg kg-1) were evaluated. In each experiment, one group of animals was kept as control. The animals were evaluated from the 3rd to the 14th day after castration process/treatment. The efficacy values for both active principles were ≤30% the next day 10 post-treatment (PT), and in five experiments, both ivermectin and abamectin, regardless of the route of administration, were ineffective (0.0%) on the day 10th PT. Based on the results found in this study, conducted in different properties from southeastern Brazil, both ivermectin and abamectin, when used the protocol presented, were considered ineffective in preventing scrotal myiasis in bulls, irrespective of the route of administration and dose used.
Espécies de Eimeria em ovinos jovens e adultos criados em sistema intensivo e / ou semi - intensivo de um rebanho da cidade de Umuarama, Estado do Paraná, Brasil
(2013-11-01) Lopes, Welber Daniel Zanetti ; Borges, Fernando de Almeida ; Faiolla, Thais de Paula ; Antunes, Liliane Tada ; Borges, Dyego Gonçalves Lino ; Rodriguez, Fernando de Souza ; Ferraro, Gisela ; Teixeira, Weslen Fabricio ; Maciel, Willian Giquelin ; Felippelli, Gustavo ; da Costa, Alvimar José ; Pereira, Valdomiro ; Martinez, Antônio Campanha ; Universidade Estadual de Maringá (UEM) ; Universidade Federal de Mato Grosso do Sul (UFMS) ; Universidade Estadual Paulista (UNESP)
The present study aimed to identify Eimeria species in young and adult sheep raised under intensive and / or semiintensive systems of a herd from Umuarama city, Parana State, Brazil using the traditional diagnostic methods and to correlate the infection level/types of infection in the different age/system in this herd. Fecal samples were collected from the rectum of 210 sheep and were subjected to laboratory analysis to differentiate the species. Furthermore, animals were observed to determine the occurrences of the clinical or subclinical forms of eimeriosis. Out of the 210 collected fecal samples, 147 (70%) were positive for Eimeria oocysts, and 101 (47.86%) belonged to young animals that were raised under intensive and / or semi-intensive farming systems. Oocysts from 9 species of Eimeria parasites were identified in the sheep at the following prevalence rates: E. crandallis, 50.0%; E. parva, 21.6%; E. faurei, 8.1%; E. ahsata, 8.1%; E. intricata, 5.4%; E. granulosa, 2.7%; E. ovinoidalis, 2.0%; E. ovina, 1.3%; and E. bakuensis, 0.6%. There were no differences regarding the more frequent Eimeria species among the different ages of animals or between the different farming management systems. Based on these data, E. crandallis was the most prevalent, followed by E. parva and E. faurei species, regardless of the age. Higher parasitism was diagnosed in the young animals that were raised in a confinement regime, and the disease found in the herd was classified as subclinical. Further studies should be conducted in this herd, to verify if the eimeriosis subclinical can cause damage especially in young animals with a high level of infection.
Occurrence de Leishmania spp. in domestic cats from Araçatuba, SP
(2010-01-01) Bresciani, Katia Denise Saraiva ; Serrano, Ana Claudia Marques ; de Matos, Lucas Vinicius Shigaki ; Savani, Elisa San Martin Mouriz ; D'Auria, Sandra Regina Nicoletti ; Perri, Silvia Helena Venturoli ; Bonello, Fabio Luiz ; Coelho, Willian Marinho Dourado ; Aoki, Carolina Godoi ; da Costa, Alvimar José ; Universidade Estadual Paulista (UNESP) ; Centro de Controle de Zoonoses de São Paulo - CCZ
This study had the purpose to compare the occurrence of Leishmania spp. in felines through two methods (cytological and serological), as well as to associate the occurrence of this protozoan with the sex, age and breed variables. Serum samples from 283 domestic felines were processed by means of Indirect Immunofluorescence Reaction (IIR), and the direct parasitological test for linfonodes was also carried out in order to verify positivity for Leishmania spp. Occurrence of 0.7% (2/283) was observed in the tested felines by means of linfonode imprinting and no animal showed title of antibodies for Leishmania spp. The two positive females were mongrel, a young female and an adult female feline. From the obtained results, no statistically significant difference was observed as regards the sex, breed and age variables in this research (p > 0.05). Occurrence of Leishmania spp. in the cats of this study was low. Such low incidence suggests that these hosts has no epidemiological relevance in the study area.
Effectiveness of the compound Chlorpyrifos+Cypermethrin+Citronellal against Alphitobius diaperinus. Laboratory analysis and residue determination in carcasses
(2007-01-01) Silva, G. S. ; Michels, M. G. ; Toma, S. B. ; Terra, F. E. ; Soares, V. E. ; Costa, A. J. ; APTA/SAA ; Ouro Fino Animal Health Ltda. ; Universidade Estadual Paulista (UNESP) ; Pólo Regional do Noroeste Paulista/APTA/SAA
Effectiveness, biological security and the absence of residues in meat and/or eggs must be considered when recommending options for the control Alphitobius diaperinus in poultry production environments. This research study evaluated the effectiveness of cypermethrin+ chlorpyrifos+citronellal in the control of A. diaperinus, including analysis for the presence of residues of this compound in poultry carcasses (experimental farm). Two studies were carried out under laboratory conditions. One used paper filters a four dilutions of the compound, and the other used a container including with pulverized broiler litter and the compound. The analysis of carcasses for residues was conducted in broilers that raised in a broiler house treated (floor and/or litter) with the compound at a dilution of 1:800. Birds were regularly sacrificed, submitted to necropsy, and liver, muscle and fat fragments were collected. Gas chromatography was used to identify the possible presence of any chemical residue in these samples. High effectiveness rates against A.diaperinus were observed in the two laboratory studies, as well as the absence of residues in the carcasses. This compound, used in the studied concentrations, can be recommended as a valuable alternative for the control and treatment of A. diaperinus.
Prevalence and risk factors for agents causing diarrhea (Coronavirus, Rotavirus, Cryptosporidium spp., Eimeria spp., and nematodes helminthes) according to age in dairy calves from Brazil
(2020-03-01) Cruvinel, Leonardo Bueno ; Ayres, Henderson ; Zapa, Dina María Beltrán ; Nicaretta, João Eduardo ; Couto, Luiz Fellipe Monteiro ; Heller, Luciana Maffini ; Bastos, Thiago Souza Azeredo ; Cruz, Breno Cayeiro ; Soares, Vando Edésio ; Teixeira, Weslen Fabricio ; de Oliveira, Juliana Silva ; Fritzen, Juliana Tomazi ; Alfieri, Amauri Alcindo ; Freire, Roberta Lemos ; Lopes, Welber Daniel Zanetti ; Universidade Federal de Goiás (UFG) ; MSD Saúde Animal ; Universidade Estadual Paulista (Unesp) ; Universidade Brasil – Campus de Descalvado ; Universidade Estadual de Londrina (UEL)
The present study attempted to verify the prevalence of and risk factors for diarrhea-causing agents in dairy calves from Brazil. Additionally, ages with a higher risk of occurrence for each agent were verified by means of the receiver operating characteristic (ROC) curve. The collections were performed on 39 farms, belonging to 29 municipalities located in eight states of Brazil. It was possible to conclude that the prevalence of Coronavirus, Rotavirus, Cryptosporidium spp., Eimeria spp., and nematodes was 7.20% (95% CI 4.54–9.78), 6.37% (95% CI 3.85–8.89), 51.52% (95% CI 45.26–55.57), 3.46% (95% CI 2.24–4.67), and 3.46% (95% CI 2.24–4.67), respectively. Ages with higher probabilities of occurrence of these diseases in calves were < 10, > 8, > 6, > 37, and > 36 days, respectively. Diarrhea occurred more significantly (P < 0.0001) in animals less than 21 days old and mainly on those receiving milk through automatic feeders (P < 0.001). Cryptosporidium spp. were a risk factor for the occurrence of Rotavirus, and vice versa (P = 0.0039) and presented a positive correlation with Coronavirus (P = 0.0089). Calves that drink water from rivers, streams, and ponds had a higher chance of being infected by Eimeria spp. (P < 0.0001), as well as developing infection by nematodes (P < 0.0001). The results found in this study highlight the importance of studying the agents of diarrhea together, once they act as coinfection where the losses triggered for the owners will involve some of these agents simultaneously.
Viability of Haemonchus placei parasitism in experimentally infected young goats
(2019-07-01) dos Santos, Isabella Barbosa ; Giquelin Maciel, Willian ; Felippelli, Gustavo ; Barbosa Toscano, João Henrique ; Cayeiro Cruz, Breno ; De Souza Chagas, Ana Carolina ; Soares, Vando Edésio ; Zanetti Lopes, Welber Daniel ; da Costa, Alvimar José ; de Oliveira, Gilson Pereira ; Universidade Estadual Paulista (Unesp) ; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) ; Universidade Federal de Goiás (UFG)
The present study aimed to evaluate the viability of Haemonchus placei parasitism in experimentally infected goats. For that, 14 75 days old kids male Saanen kids were placed in one of the four experimental groups: GI – infected with 5000 H. placei L3 (n = 4); GII – infected with 5000 H. contortus L3 (n = 4); GIII – infected with 2500 H. contortus L3 + 2500 H. placei L3 (n = 4), and GIV – control, inoculated with distilled water (n = 2). Each kid received, orally, the infective dose in a single inoculum. Based on daily fecal egg counts, the average pre-patent period was determined as 24 days for H. contortus, and 31 days for H. placei. Regarding the Haemonchus spp. recovered at necropsy, the experimental groups GI, GII, and GIII had, respectively, an average of 25.5, 619.5, and 724.75 (120 H. placei, and 604.75 H. contortus) adult specimens, and no immature forms. Under the conditions of this study, the viability of goat infection by H. placei was confirmed, although, with low susceptibility. Nevertheless, the parasitism of this helminth species was more intense when associated with H. contortus. This fact indicates that in common grazing between cattle and young goats, when the latter end up ingesting both Haemonhcus species, especially in a mixed infection, H. placei may also parasitize them.
In vivo effect of diflubenzuron, administered via mineral salt supplementation, against haematobia irritans and rhipicephalus microplus parasitizing cattle
(2018-10-01) Cruz, Breno Cayeiro ; Gomes, Lucas Vinicius Costa ; Maciel, Willian Giquelin ; Felippelli, Gustavo ; Dos Santos, Isabella Barbosa ; Cruvinel, Leonardo Bueno ; Couto, Luiz Fellipe Monteiro ; Bastos, Thiago Souza Azeredo ; Cavalcante, Alliny Souza de Assis ; Nicaretta, João Eduardo ; Soares, Vando Edésio ; da Costa, Alvimar José ; Lopes, Welber Daniel Zanetti ; Universidade Estadual Paulista (Unesp) ; Universidade Federal de Goiás (UFG) ; Universidade Brasil
This study involved two field trials with the aim of evaluating the efficacy of diflubenzuron, via mineral supplementation, against Haematobia irritans parasitizing cattle. Concomitantly with the main trial, a stall test was conducted to ascertain the effects of a different formulation with the same active ingredient against Rhipicephalus microplus, along with the action of diflubenzuron on the reproductive parameters of R. microplusfemales that had naturally detached from cattle. Against H. irritans, it was observed that the efficacy indexes fordiflubenzuron were low (≤ 31.3% or 44.6%) or null (0.0%) throughout the study. The anti-R. microplus efficacy of diflubenzuron, at weekly intervals, ranged from 0.0 to 13.7% over the entire experimental period. Null efficacy (0.0%) was registered for diflubenzuron in relation to the reproductive parameters of R. microplusfemales that had naturally detached from cattle. The different diflubenzuron formulations, administered via mineral salt supplementation, did not show satisfactory efficacy indexes against H. irritans and R. microplus parasitizing cattle, within the experimental design of the present study. In addition, this agent did not present any deleterious effects on the reproductive parameters of R. microplus females.
Spatial distribution and risk factors for Toxoplasma gondii seropositivity in cattle slaughtered for human consumption in Rondônia, North region, Brazil
(2016-08-15) de Souza, Juliana Bianca Rocha ; Soares, Vando Edésio ; Maia, Maerle Oliveira ; Pereira, Cleidiane Magalhães ; Ferraudo, Antônio Sergio ; Cruz, Breno Cayeiro ; Pires Teixeira, Weslen Fabrício ; Felippelli, Gustavo ; Maciel, Willian Giquelin ; Gonçalves, Walter Antonio ; da Costa, Alvimar José ; Zanetti Lopes, Welber Daniel ; UNICASTELO – Universidade Camilo Castelo Branco ; Universidade Estadual Paulista (Unesp) ; Universidade Estadual de Maringá (UEM) ; Universidade Federal de Goiás (UFG)
The present study aimed to evaluate Toxoplasma gondii seroprevalence in cattle slaughtered for human consumption from rural properties in the state of Rondônia, North region, Brazil; the seroprevalence was determined using indirect immunofluorescence assays (IFATs). Additionally, spatial distribution and risk factors associated with toxoplasmosis were also analyzed. Of the 1000 cattle serum samples examined, 53 (5.3%) were determined to be seropositive for T. gondii with antibody titers (IgG) ≥64. In regard to results of the studied risk factors (presence of cats, cats with free access to cattle, breeding system, animal's gender, consumption of raw milk by humans on the property and cattle abortion in the last 12 months) and the odds ratio (OR) of each of these factors influencing cattle to acquire toxoplasmosis, only animals raised on a feeder/stocker/backgrounder system presented a higher probability of being seropositive for T. gondii (OR ≥ 1, P = 0.04) than cattle raised only in a feeder/stocker system. There was no association between the occurrence of reproductive problems and T. gondii seropositivity. Based on results obtained in the Brazilian state of Rondônia, it could be concluded that the presence of cats and their contact with cattle on each property, cattle breeding purpose and cattle abortion in the last 12 months were not considered risk factors for T. gondii infection in cattle. Considering that the presence of T. gondii was detected in animals slaughtered in the state of Rondônia, consuming raw or undercooked meat from seropositive cattle should be considered a route of transmission of T. gondii to humans. However, the prevalence of toxoplasmosis diagnosed in cattle from this state (5.30%) is lower than the prevalence of toxoplasmosis observed in South, Southeast and Center-West regions of Brazil, which may vary between 48.5% and 71.0%. The low prevalence of toxoplasmosis in cattle is highlighted in Rondônia, which is the sixth largest state for cattle slaughtering in Brazil and is responsible for producing 20% of all cattle meat exported by Brazil.
Avermectin toxicity in bovines less than thirty days old
(2018-06-01) de Castro Rodrigues, Daniel ; Buzullini, Carolina ; Pereira, Tiago Arantes ; Curz, Breno Cayeiro ; Gomes, Lucas Vinicius Costa ; Soares, Vando Edésio ; Bastos, Thiago Souza Azeredo ; Couto, Luiz Fellipe Monteiro ; Lopes, Welber Daniel Zanetti ; de Oliveira, Gilson Pereira ; Costa, Alvimar José da ; MSD Animal Health ; Universidade Estadual Paulista (Unesp) ; Universidade Brasil ; Universidade Federal de Goiás (UFG)
The present study was designed to evaluate possible adverse effects of different dosages of avermectins (abamectin and a combination of ivermectin + abamectin) administered subcutaneously in calves less than one month of age. Clinical as well as biochemical parameters of blood and cerebrospinal fluid (CSF) were evaluated for animals subjected to various treatments. Thirty-five calves were divided into seven groups of five animals each: T01 (control), T02 (abamectin 200 μg/kg), T03 (abamectin 400 μg/kg), T04 (abamectin 600 μg/kg), T05 (ivermectin 450 μg/kg + abamectin 250 μg/kg), T06 (ivermectin 900 μg/kg + abamectin 500 μg/kg) and T07 (ivermectin 1350 μg/kg + abamectin 750 μg/kg). Cerebrospinal fluid and blood samples were collected on day zero (treatment day) and on days 1, 7 and 14 following treatment. The biochemical parameters measured in blood samples were total protein and the AST, GGT and alkaline phosphatase enzymes. In CSF samples, color, aspects, pH, density, cellularity, total proteins, glucose and the CK, ALT and LDH enzymes were evaluated. No neurological toxicity or biochemical changes in the CSF or blood that could be correlated to administration of tested products were observed in this study. Though it is well known that abamectin may lead to intoxication in bovines less than four months of age, based on data from the present study, no adverse clinical effects to the CSF or blood were observed in calves <30 days old that had received up to 600 μg/kg abamectin formulations and up to 1350 μg/kg ivermectin +750 μg/kg abamectin associations. It is possible that the level and activity of the multiple drug resistance gene (MDR1 - ABCB1) present in the calves may have influenced the results obtained in this study. Future studies should be carried out.
Investigation of Toxoplasma gondii in semen, testicle and epididymis tissues of primo-infected cats (Felis catus)
(2017-04-30) Teixeira, Weslen Fabricio Pires ; Tozato, Maria Eduarda Gonçalves ; Pierucci, Julia Cestari ; Vital, Giovana Pavão ; Cruz, André Cayeiro ; Lopes, Welber Daniel Zanetti ; Cursino, Marina Suzuki ; Joaquim, Samea Fernandes ; Soares, Vando Edésio ; Langoni, Helio ; Bresciani, Kátia Denise Saraiva ; Costa, Alvimar José da ; Universidade Estadual Paulista (Unesp) ; Universidade Federal de Goiás (UFG) ; Universidade Brasil – Campus Descalvado
This study aimed to investigate the presence of Toxoplasma gondii in semen, testicle and epididymis tissues of cats experimentally infected by this coccidium. A total of 12 male felines without a definite breed that were of reproductive age and serologically negative for T. gondii were selected and distributed to the following three experimental groups: GI, inoculated with 600 tissue cysts of the P strain of T. gondii (isolate III); GII, inoculated with 2 × 105 tachyzoites of the RH strain (isolate I); and GIII, not inoculated (control group). Prior to inoculation (day −7 and 0) and on post inoculation days (PIDs) 7, 14, 21, 28, 42, 56, and 70, all felines were subjected to assessments of anti-T. gondii IgG by indirect immunofluorescence (IIF) and assessments of parasitemia. Collection of semen (electroejaculation) was performed on the specified dates, followed by nested PCR and bioassays in mice to detect T. gondii. On PID 70, all 12 felines were orchiectomized, and the presence of the parasite in the testicles and epididymides was evaluated by nested PCR, murine bioassay, and histopathological and immunohistochemical analyses. All felines inoculated with T. gondii (GI and GII) seroconverted to the toxoplasmic infection after PID 14; on PID 7, seroconversion of three felines (P4, RH2 and RH4) could observed, and all exhibited detectable titers by PID 64. The GII felines exhibited greater serological titers compared with GI felines. The maximum serological titer (IgG) was observed in feline RH3 (titer 1024), while in other experimental felines, a maximum titer of 256 was detected. Parasitemic peaks were diagnosed in all felines of groups I and II from PIDs 7–42. A total of five parasitemic peaks were diagnosed in GI and nine in GII. In none of the experimental time points was the presence of T. gondii diagnosed in seminal samples collected from the felines or in the testicle or epididymis tissues collected from these animals. Thus, sexual transmission in domestic cats does not appear to be a major route of T. gondii infection, possibly demonstrating the tendency of this protozoan to develop a response directed to the formation and excretion of oocysts in the feces of these definite hosts, which act as its main route of perpetuation in the environment.
Life cycle and parasitic competence of Dermacentor nitens Neumann, 1897 (Acari: Ixodidae) on different animal species
(2017-03-01) Rodrigues, Vinicius da Silva ; Garcia, Marcos Valério ; Cruz, Breno Cayeiro ; Maciel, Willian Giquelin ; Zimmermann, Namor Pinheiro ; Koller, Wilson Werner ; Barros, Jacqueline Cavalcante ; Andreotti, Renato ; Universidade Federal de Mato Grosso do Sul (UFMS) ; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) ; Universidade Estadual Paulista (Unesp)
The objective of this study was to evaluate the life cycle and parasitic competence of Dermacentor nitens (Neumann, 1897) on different animal species. Experimental infestations were induced in five specimens each of seven species of possible hosts: rabbits, horses, sheep, cows, guinea pigs, birds and dogs. Rabbits were infested in the ear using artificial feeding chambers, and the horses, sheep, cows and dogs were infested in the ear without feeding chambers. For the infestation of guinea pigs, artificial feeding chambers were fixed on the back. Birds were infested by placing larvae on the back and under the wings without the use of chambers. All animals were inspected daily until the end of the parasitic phase (when the engorged females detached). The average period of engorgement was 25.1 days on a horse, with larvae requiring 8 days and nymphs 9 days to reach engorgement; the average weight of engorged females was 271.4 mg; the average weight of egg batches produced was 159.3 mg, and the feed conversion rate was 56.8%. On rabbits, the average engorgement period was 27.6 days, larvae and nymphs reached engorgement after 7.4 and 11 days, respectively, the average weight of an engorged female was 108.4 mg and the egg mass was 30.6 mg. The feed conversion rate on rabbits was 30%. Cows, sheep, guinea pigs, dogs and birds were not competent hosts, since no engorged females were recovered. Rabbits, when artificially infested, can be used as an alternative host for the maintenance of these ticks in the laboratory. The parasitic specificity of D. nitens for horses was demonstrated in this study.
Population dynamics and evaluation of the partial selective treatment of crossbreed steers naturally infested with Rhipicephalus (Boophilus) microplus in a herd from the state of Minas Gerais in Brazil
(2016-04-15) Costa Gomes, Lucas Vinicius ; Lopes, Welber Daniel Zanetti ; Teixeira, Weslen Fabricio Pires ; Maciel, Willian Giquelin ; Cruz, Breno Cayeiro ; Felippelli, Gustavo ; Buzzulini, Carolina ; Soares, Vando Edésio ; Melo, Daniel Pacheco de ; Bichuette, Murilo Abud ; Gonçalves, Geraldo ; da Costa, Alvimar José ; Universidade Estadual Paulista (Unesp) ; Universidade Federal de Goiás (UFG) ; UNICASTELO—Universidade Camilo Castelo Branco
The present study aimed to evaluate the population dynamics of Rhipicephalus (Boophilus) microplus over a period of 13 months on a rural property located in the state of Minas Gerais in southeastern Brazil. Animals were treated for ticks indoors by whole body spraying when R. (B.) microplus had an average count equal or more than 30 ticks. The study also evaluated the possibility of a partial selective treatment for bovines to control R. (B.) microplus in which only a percentage of the population would be treated (specifically those bovines with tick counts of ≥20. Moreover, we examined the percentage of the population of R. (B.) microplus present on experimental bovines that did not come into contact with the chemical compounds used in the partial selective treatment. We concluded that in this particular region of Brazil, the crossbreed steers support up to five R. (B.) microplus generations per year and that the number of generations was primarily affected by the pluviometric precipitation. We sprayed the bovines with chemicals seven times during the course of the study. The results of the partial selective treatment method revealed that during the rainy and the dry periods, 42.1% to 60.0% and 61.9% to 79.2% of the animals, respectively, fulfilled the criteria to receive a chemical treatment to reduce the number of cattle ticks. In consideration of the need to slow the development of tick resistance with the chemical compounds used in the spraying treatment, the results showed that the percentage of animals that did not require treatment is not relevant. This was evidenced by the result that bovines that presented tick counts of ≥20 during the dry and rainy periods represented 91.5% and 90.6% of the total recorded R. (B.) microplus populations, respectively. Only 8.7% of the tick population remained free from exposure to acaricides during the 13 months of the study, which is an important point when considering the adoption of the partial selective treatment method. Future studies with larger herds must be conducted on these topics; however, our results suggest that the partial selective treatment method most likely will not slow the development of resistance in this R. (B.) microplus population against the chemical compound used in this study.
Susceptibility of Rhipicephalus (Boophilus) microplus to fluazuron (2.5 mg/kg) and a combination of novaluron (2.0 mg/kg) + eprinomectin (0.36 mg/kg) in field studies in Brazil
(2016-12-01) Maciel, Willian Giquelin ; Lopes, Welber Daniel Zanetti ; Gomes, Lucas Vinicius Costa ; Cruz, Breno Cayeiro ; Felippelli, Gustavo ; Santos, Isabella Barbosa Dos ; Borges, Fernando de Almeida ; Gonçalves, Walter Antonio ; Scarpa, Alexandre Braga ; Nicaretta, João Eduardo ; Bastos, Thiago Souza Azeredo ; da Costa, Alvimar José ; Universidade Estadual Paulista (Unesp) ; Universidade Federal de Goiás (UFG) ; Universidade Federal de Mato Grosso do Sul (UFMS) ; Universidade Estadual de Maringá (UEM)
The present study aimed to determine the susceptibility of 32 R. (B.) microplus populations from Southeast, Midwest and South regions of Brazil, to fluazuron (2.5 mg/kg), administered topically (pour-on). Additionally, five populations (Southeast and Midwest regions) of the southern cattle tick were evaluated using in vivo field studies, regarding their susceptibility to a new combination of novaluron (2.0 mg/kg) + eprinomectin (0.36 mg/kg), administered subcutaneously, compared with two positive controls (fluazuron 2.5 mg/kg and eprinomectin 0.5 mg/kg), both administered topically (pour-on). Selected bovines were allocated to treatment groups on day 0, and block formation was based on arithmetic means of female ticks (4.5–8.0 mm long) counted on three consecutive days (−3, −2 and −1). To evaluate therapeutic and residual efficacies of these formulations, tick counts (females ranging from 4.5 to 8.0 mm long) were performed on days 3, 7 and 14 post-treatment, continuing on a weekly basis until the end of each experiment. Results obtained throughout this study, utilizing field efficacy trials, allowed us to conclude that four R. (B.) microplus populations (including two in the Southeast and two in the Midwest regions) could be diagnosed as resistant, or with low susceptibility, to fluazuron (2.5 mg/kg). Such fact was detected in farms where owners applied products containing this active component on cattle for at least five years, with treatment intervals of 30–55 days during the rainy season. Nonetheless, in vitro studies should be performed in order to reinforce in vivo results obtained on the present study. Regarding efficacy indexes obtained by the association of eprinomectin and the novel molecule novaluron against R. (B.) microplus, none of the trials managed to obtain efficacies superior to 48%. Such results, allied to data obtained by different researchers and previously published in literature, reinforce the perception that maybe these formulations containing novaluron, in the administered dosages and treatment routes, may not be effective tools for controlling R. (B.) microplus. However, future studies must be conducted in order to support such hypothesis. Additionally, all five R. (B.) microplus populations were diagnosed as resistant, or with low susceptibility, to eprinomectin (0.5 mg/kg) as well. Even though fluazuron, administered topically (pour on), is still an excellent active principle to be used against R. (B.) microplus, resistance management strategies should be quickly implemented in order to keep selection pressure in Brazil at a minimum level for this compound.
Congenital toxoplasmosis in chronically infected and subsequently challenged ewes
(2016-10-01) Dos Santos, Thaís Rabelo ; Faria, Gabriela Da Silva Magalhães ; Guerreiro, Bruna Martins ; Dal Pietro, Nathalia Helena Pereira Da Silva ; Lopes, Welber Daniel Zanetti ; Da Silva, Helenara Machado ; Garcia, João Luis ; Luvizotto, Maria Cecília Rui ; Bresciani, Katia Denise Saraiva ; Da Costa, Alvimar José ; Rolim de Moura ; Universidade Estadual Paulista (Unesp) ; UEL
This experiment studied congenital transmission in sheep experimentally infected with oocysts of Toxoplasma gondii and reinfected at one of three stages of pregnancy. Twenty ewes were experimentally infected with T. gondii strain ME49 (day 0). After the T. gondii infection became chronic (IFAT≤512), the ewes were allocated with rams for coverage. After the diagnosis of pregnancy, these ewes were allocated into four experimental groups (n = 5): I-reinfected with T. gondii on the 40th day of gestation (DG); II-reinfected on DG 80; III-reinfected on DG 120; and IV-saline solution on DG 120 (not reinfected). Five ewes (IFAT<64) were kept as negative controls (uninfected, group V), therefore in groups I-III were infected prior to pregnancy and re-infected during pregnancy, group IV was only infected prior to pregnancy, and group V was not infected. Parasitism by T. gondii was investigated (histopathology, immunohistochemistry, mouse bioassay and PCR) in mothers and lambs tissue. All ewes produced lambs serologically positive for T. gondii. The results of the mouse bioassay, immunohistochemistry and PCR assays revealed the presence of T. gondii in all 20 sheep and their lambs. The congenital transmission of T. gondii was associated with fetal loss and abnormalities in persistently infected sheep and in ewes infected and subsequently reinfected by this protozoan. Therefore, congenital T. gondii infection was common when ewes were chronically infected prior to pregnancy, with or without reinfection during at various stages of gestation.
Experimental infection of calves with Haemonchus placei or Haemonchus contortus: Assessment of clinical, hematological and biochemical parameters and histopathological characteristics of abomasums
(2016-11-01) Fávero, Flávia Carolina ; Buzzulini, Carolina ; Cruz, Breno Cayeiro ; Felippelli, Gustavo ; Maciel, Willian Giquelin ; Salatta, Bruna ; Siniscalchi, Débora ; Lopes, Welber Daniel Zanetti ; Teixeira, Weslen Fabricio Pires ; Soares, Vando Edésio ; de Oliveira, Gilson Pereira ; da Costa, Alvimar José ; Universidade Estadual Paulista (Unesp) ; Universidade Federal de Goiás (UFG) ; Universidade Camilo Castelo Branco (Unicastelo)
The present study had the primary objective of evaluating clinical, hematological and biochemical parameters, as well as observing anatomical and histopathological characteristics of abomasums, from calves prime-infected with Haemonchus contortus or H. placei. Ten male Holstein newborns were subdivided in three groups (GI placebo; GII infected with H. contortus; GIII inoculated with H. placei). Eye mucosa staining was evaluated. Hematological and biochemical tests were performed on animals. The euthanasia of all ten experimental calves was performed on the 42nd day post-inoculation. Fragments were collected from each of all 10 abomasums for histopathological analysis. Discrete submandibular edema was diagnosed in animals from both infected groups (H. contortus or H. placei). However, there were no significant changes (P > 0.05) in the color of the ocular mucosa of calves from all three experimental groups across the entire experimental period. Hematological and biochemical changes diagnosed on animals could not be linked to infections by species of Haemonchus spp. Regarding histopathological exams, it was possible to diagnose hypertrophy, hyperplasia, binucleated cells, inflammatory infiltrate, multifocal hemorrhage and edema in abomasums from calves of both groups infected with H. placei and H. contortus. It can, thus, be concluded that not only are calves susceptible to infections by both Haemonchus species, but they can also present clinical changes and similar anatomic histopathological lesions independent of being infected by Haemonchus placei or Haemonchus contortus. These results reflect a negative effect on helminth control by mixed grazing between sheep and cattle, especially when using calves.
Experimental infection of calves with Haemonchus placei and Haemonchus contortus: Assessment of parasitological parameters
(2016-01-01) Fávero, Flávia Carolina ; Buzzulini, Carolina ; Cruz, Breno Cayeiro ; Felippelli, Gustavo ; Maciel, Willian Giquelin ; Salatta, Bruna ; Teixeira, Weslen Fabricio Pires ; Soares, Vando Edésio ; de Oliveira, Gilson Pereira ; Lopes, Welber Daniel Zanetti ; da Costa, Alvimar José ; Universidade Estadual Paulista (Unesp) ; Universidade Federal de Goiás (UFG)
The present study evaluated the viability and possible effects of Haemonchus contortus infections in experimentally prime infected calves, comparing them to infections by Haemonchus placei. Ten male Holstein newborns were used. All calves were individually weighed for subsequent group formation, in which two animals were kept as a control group, inoculated with water (GI); four animals were inoculated with 10,000 third stage (L3) Haemonchus contortus larvae (GII); and the remaining four calves were inoculated with 10,000 third stage (L3) H. placei larvae (GIII). All experimental animals were necropsied on the 42nd day after inoculation. Based on results obtained by the present study, it can be concluded that bovine calves were susceptible to infections by both Haemonchus species (placei and contortus). H. contortus presented an inferior pre-patent period when compared to H. placei. No significant difference (P > 0.05) was observed between Haemonchus burdens recovered from both infected groups (GII and GIII). Moreover, H. contortus females maintained an egg production rate similar to H. placei females in young animals, which can contribute to pasture contamination by both Haemonchus species. This could possibly lead to negative reflexes on helminth control based on a mixed pasture with bovines and ovines, especially when it involves younglings.

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